المؤلفون: Yates, D., Kruecken, R., Dillmann, I., Garrett, P. E., Olaizola, B., Vedia, V., Ali, F. A., Andreoiu, C., Ashfield, W., Ball, G. C., Beadle, Z., Bernier, N., Bhattacharjee, S. S., Bidaman, H., Bildstein, V., Bishop, D., Bowry, M., Burbadge, C., Caballero-Folch, R., Chaney, D. Z., Cross, D. C., Varela, A. Diaz, Dunlop, M. R., Dunlop, R., Evitts, L. J., Garcia, F. H., Garnsworthy, A. B., Georges, S., Gillespie, S. A., Hackman, G., Henderson, J., Jigmeddorj, S., Lassen, J., Li, R., Luna, B. K., MacLean, A. D., Natzke, C. R., Petrache, C. M., Radich, A. J., Rajabali, M. M., Regan, P. H., Saito, Y., Smallcombe, J., Smith, J. K., Spieker, M., Svensson, C. E., Whitmore, A. Teigelhoefer K., Zidar, T.

مصطلحات موضوعية: Nuclear Experiment

الوصف: \noindent \textbf{Background:} Detailed spectroscopy of neutron-rich, heavy, deformed nuclei is of broad interest for nuclear astrophysics and nuclear structure. Nuclei in the r-process path and following freeze-out region impact the resulting r-process abundance distribution, and the structure of nuclei midshell in both proton and neutron number helps to understand the evolution of subshell gaps and large deformation in these nuclei. \noindent \textbf{Purpose:} To improve the understanding of the nuclear structure of $^{160}$Gd, specifically the $K^\pi$=$4^+$ bands, as well as study the $\beta$-decay of $^{160}$Eu into $^{160}$Gd. \noindent \textbf{Methods:} High-statistics decay spectroscopy of $^{160}$Gd resulting from the $\beta$-decay of $^{160}$Eu was collected using the GRIFFIN spectrometer at the TRIUMF-ISAC facility. \noindent \textbf{Results:} Two new excited states and ten new transitions were observed in $^{160}$Gd. The $\beta$-decaying half-lives of the low- and high-spin isomer in $^{160}$Eu were determined, and the low-spin state's half-life was measured to be $t_{1/2}=26.0(8)$~s, $\sim$16\% shorter than previous measurements. Lifetimes of the two $K^\pi$=$4^+$ band-heads in $^{160}$Gd were measured for the first time, as well as $\gamma$-$\gamma$ angular correlations and mixing ratios of intense transitions out of those band-heads. \noindent \textbf{Conclusions:} Lifetimes and mixing ratios suggest that the hexadecapole phonon model of the $K^\pi$=$4^+$ band-heads in $^{160}$Gd is preferred over a simple two-state strong mixing scenario, although further theoretical calculations are needed to fully understand these states. Additionally, the 1999.0 keV state in $^{160}$Gd heavily populated in $\beta$-decay is shown to have positive parity, which raises questions regarding the structure of the high-spin $\beta$-decaying state in $^{160}$Eu.

الوصول الحر: http://arxiv.org/abs/2305.11324Test

المؤلفون: Yates, D, Krücken, R, Dillmann, I, Garrett, PE, Olaizola, B, Vedia, V, Ali, FA, Andreoiu, C, Ashfield, W, Ball, GC, Beadle, Z, Bernier, N, Bhattacharjee, SS, Bidaman, H, Bildstein, V, Bishop, D, Bowry, M, Burbadge, C, Caballero-Folch, R, Chaney, DZ, Cross, DC, Varela, A Diaz, Dunlop, MR, Dunlop, R, Evitts, LJ, Garcia, FH, Garnsworthy, AB, Georges, S, Gillespie, SA, Hackman, G, Henderson, J, Jigmeddorj, B, Lassen, J, Li, R, Luna, BK, MacLean, AD, Natzke, CR, Petrache, CM, Radich, AJ, Rajabali, MM, Regan, PH, Saito, Y, Smallcombe, J, Smith, JK, Spieker, M, Svensson, CE, Teigelhöfer, A, Whitmore, K, Zidar, T

المصدر: Physical Review C. 107(6)

مصطلحات موضوعية: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics

الوصف: Background: Detailed spectroscopy of neutron-rich, heavy, deformed nuclei is of broad interest for nuclear astrophysics and nuclear structure. Nuclei in the r-process path and following freeze-out region impact the resulting r-process abundance distribution, and the structure of nuclei midshell in both proton and neutron number helps to understand the evolution of subshell gaps and large deformation in these nuclei. Purpose: We aim to improve the understanding of the nuclear structure of Gd160, specifically the Kπ=4+ bands, as well as study the β decay of Eu160 into Gd160. Methods: High-statistics decay spectroscopy of Gd160 resulting from the β-decay of Eu160 was collected using the GRIFFIN spectrometer at the TRIUMF-ISAC facility. Results: Two new excited states and ten new transitions were observed in Gd160. The β-decaying half-lives of the low- and high-spin isomers in Eu160 were determined, and the low-spin state's half-life was measured to be t1/2=26.0(8) s, ≈16% shorter than previous measurements. Lifetimes of the two Kπ=4+ bandheads in Gd160 were measured for the first time, as well as γ-γ angular correlations and mixing ratios of intense transitions out of those bandheads. Conclusions: Lifetimes and mixing ratios suggest that the hexadecapole phonon model of the Kπ=4+ bandheads in Gd160 is preferred over a simple two-state strong mixing scenario, although further theoretical calculations are needed to fully understand these states. Additionally, the 1999.0-keV state in Gd160 heavily populated in β decay is shown to have positive parity, which raises questions regarding the structure of the high-spin β-decaying state in Eu160.

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/0hb6r7czTest
https://escholarship.org/content/qt0hb6r7cz/qt0hb6r7cz.pdfTest

المؤلفون: Garnsworthy, A. B., Svensson, C. E., Bowry, M., Dunlop, R., MacLean, A. D., Olaizola, B., Smith, J. K., Ali, F. A., Andreoiu, C., Ash, J. E., Ashfield, W. H., Ball, G. C., Ballast, T., Bartlett, C., Beadle, Z., Bender, P. C., Bernier, N., Bhattacharjee, S. S., Bidaman, H., Bildstein, V., Bishop, D., Boubel, P., Braid, R., Brennan, D., Bruhn, T., Burbadge, C., Cheeseman, A., Chester, A., Churchman, R., Ciccone, S., Caballero-Folch, R., Cross, D. S., Cruz, S., Davids, B., Varela, A. Diaz, Dillmann, I., Dunlop, M. R., Evitts, L. J., Garcia, F. H., Garrett, P. E., Georges, S., Gillespie, S., Gudapati, R., Hackman, G., Hadinia, B., Hallam, S., Henderson, J., Ilyushkin, S. V., Jigmeddorj, B., Kilic, A. I., Kisliuk, D., Kokke, R., Kuhn, K., Kruecken, R., Kuwabara, M., Laffoley, A. T., Lafleur, R., Leach, K. G., Leslie, J. R., Linn, Y., Lim, C., MacConnachie, E., Mathews, A. R., McGee, E., Measures, J., Miller, D., Mills, W. J., Moore, W., Morris, D., Morrison, L. N., Moukaddam, M., Natzke, C. R., Ortner, K., Padilla-Rodal, E., Paetkau, O., Park, J., Patel, H. P., Pearson, C. J., Peters, E., Peters, E. E., Pore, J. L., Radich, A. J., Rajabali, M. M., Rand, E. T., Raymond, K., Rizwan, U., Ruotsalainen, P., Saito, Y., Sarazin, F., Shaw, B., Smallcombe, J., Southall, D., Starosta, K., Ticu, M., Timakova, E., Turko, J., Umashankar, R., Unsworth, C., Wang, Z. M., Whitmore, K., Wong, S., Yates, S. W., Zganjar, E. F., Zidar, T.

مصطلحات موضوعية: Physics - Instrumentation and Detectors, Nuclear Experiment

الوصف: Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new high-efficiency $\gamma$-ray spectrometer designed for use in decay spectroscopy experiments with low-energy radioactive ion beams provided by TRIUMF's Isotope Separator and Accelerator (ISAC-I) facility. GRIFFIN is composed of sixteen Compton-suppressed large-volume clover-type high-purity germanium (HPGe) $\gamma$-ray detectors combined with a suite of ancillary detection systems and coupled to a custom digital data acquisition system. The infrastructure and detectors of the spectrometer as well as the performance characteristics and the analysis techniques applied to the experimental data are described.

الوصول الحر: http://arxiv.org/abs/1809.07183Test

المؤلفون: Smith, J. K., MacLean, A. D., Ashfield, W., Chester, A., Garnsworthy, A. B., Svensson, C. E.

مصطلحات موضوعية: Physics - Instrumentation and Detectors, Nuclear Experiment

الوصف: Gamma-gamma angular correlation measurements are a powerful tool for identifying the angular momentum (spin) of excited nuclear states involved in a $\gamma$-ray cascade, and for measuring the multipole orders and mixing ratios of transitions. Though the physical angular correlations are fully calculable from first principles, experimental effects can make the extraction of coefficients and thus conclusions about spins and mixing ratios difficult. In this article we present data analysis techniques developed for the clover detectors of the GRIFFIN spectrometer at TRIUMF-ISAC combined with GEANT4 simulations in order to extract accurate experimental results.

الوصول الحر: http://arxiv.org/abs/1807.07570Test

المؤلفون: Caspi, A., Seaton, D., Casini, R., Downs, C., Gibson, S., Gilbert, H., Glesener, L., Guidoni, S., Hughes, J.M., McKenzie, D., Plowman, J., Reeves, K., Saint-Hilaire, P., Shih, A.Y., West, M., Alaoui, M., Alexander, D., Allred, J.C., Antiochos, S., Ashfield, W., Ballai, I., Barata, T., Barta, M., Benz, A.O., Berlicki, A., Bradshaw, S.J., Bröse, M., Buitrago-Casas, J.C., Cassak, P., Chamberlin, P., Che, H., Chen, T.Y., Chen, B., Cheng, X., Christe, S., Comisso, L., Dahlin, J., Nolfo, G.D., Dennis, B., Dickson, E.C.M., Drake, J., Dudík, J., Dzifcakova, E., Emslie, G., Erdelyi, R., Farid, S., Fleishman, G., French, R., Gallagher, P.T., Gan, W., Gary, D., Guo, F., Hayes, L.A., Hudson, H., Ji, H., Jones, A.R., Kansabanik, D., Kawate, T., Kerr, G.S., Keshav, A., Knuth, T., Kobelski, A., Kooi, J., Kumari, A., Lee, J., Li, Y., Longo, F., Maharana, A., Mandrini, C.H., Oliveros, J.C.M., Mason, J.P., Mason, E.I., Massone, A.M., McAteer, R.T.J., McConnell, M., McTiernan, J., Mitchell, J.G., Mohan, A., Motorina, G., Mrozek, T., Musset, S., Narukage, N., Nayak, S.S., Nitta, N., Panesar, N., Pariat, E., Piana, M., Pohjolainen, S., Qiu, J., Reale, F., Rivera, Y., Rozelot, J.P., Sarkar, R., Setterberg, W., Shaik, S.B., Shaikh, Z., Sharma, R., Skokic, I., Stores, M., Struminsky, A., Sylwester, J., Takahashi, T., Tiwari, S., Tsiklauri, D., Vievering, J.T., Warmuth, A., White, S., Zimovets, I.V.

الوصف: The coronal magnetic field is the prime driver behind many as-yet unsolved mysteries: solar eruptions, coronal heating, and the solar wind, to name a few. It is, however, still poorly observed and understood. We highlight key questions related to magnetic energy storage, release, and transport in the solar corona, and their relationship to these important problems. We advocate for new and multi-point co-optimized measurements, sensitive to magnetic field and other plasma parameters, spanning from optical to γ-ray wavelengths, to bring closure to these long-standing and fundamental questions. We discuss how our approach can fully describe the 3D magnetic field, embedded plasma, particle energization, and their joint evolution to achieve these objectives.

وصف الملف: text

العلاقة: https://eprints.whiterose.ac.uk/203430/1/21692975172443.pdfTest; Caspi, A. orcid.org/0000-0001-8702-8273 , Seaton, D. orcid.org/0000-0002-0494-2025 , Casini, R. orcid.org/0000-0001-6990-513X et al. (105 more authors) (2023) Magnetic energy powers the corona: how we can understand its 3D storage & release. Bulletin of the American Astronomical Society, 55 (3).

الإتاحة: https://doi.org/10.3847/25c2cfeb.1dbfea1fTest
https://eprints.whiterose.ac.uk/203430Test/
https://eprints.whiterose.ac.uk/203430/1/21692975172443.pdfTest

المؤلفون: Garnsworthy, A. B., Svensson, C. E., Bowry, M., Dunlop, R., MacLean, A. D., Olaizola, B., Smith, J. K., Ali, F. A., Andreoiu, C., Ash, J. E., Ashfield, W. H., Ball, G. C., Ballast, T., Bartlett, C., Beadle, Z., Bender, P. C., Bernier, N., Bhattacharjee, S. S., Bidaman, H., Bildstein, V., Bishop, D., Boubel, P., Braid, R., Brennan, D., Bruhn, T., Burbadge, C., Cheeseman, A., Chester, A., Churchman, R., Ciccone, S., Caballero-Folch, R., Cross, D. S., Cruz, S.

المصدر: Faculty Publications

مصطلحات موضوعية: Decay spectroscopy, HPGe, ISAC, TRIUMF

الوصف: Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new high-efficiency γ-ray spectrometer designed for use in decay spectroscopy experiments with low-energy radioactive ion beams provided by TRIUMF's Isotope Separator and Accelerator (ISAC-I) facility. GRIFFIN is composed of sixteen Compton-suppressed large-volume clover-type high-purity germanium (HPGe) γ-ray detectors combined with a suite of ancillary detection systems and coupled to a custom digital data acquisition system. The infrastructure and detectors of the spectrometer as well as the performance characteristics and the analysis techniques applied to the experimental data are described.

وصف الملف: application/pdf

العلاقة: https://digitalcommons.lsu.edu/physics_astronomy_pubs/6069Test; https://digitalcommons.lsu.edu/context/physics_astronomy_pubs/article/7149/viewcontent/6069.pdfTest

الإتاحة: https://doi.org/10.1016/j.nima.2018.11.115Test
https://digitalcommons.lsu.edu/physics_astronomy_pubs/6069Test
https://digitalcommons.lsu.edu/context/physics_astronomy_pubs/article/7149/viewcontent/6069.pdfTest

المؤلفون: Smith, J.K., MacLean, A.D., Ashfield, W., Chester, A., Garnsworthy, A.B., Svensson, C.E.

المساهمون: Natural Sciences and Engineering Research Council of Canada

المصدر: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment ; volume 922, page 47-63 ; ISSN 0168-9002

مصطلحات موضوعية: Instrumentation, Nuclear and High Energy Physics

الإتاحة: https://doi.org/10.1016/j.nima.2018.10.097Test
https://api.elsevier.com/content/article/PII:S0168900218314116?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S0168900218314116?httpAccept=text/plainTest

المؤلفون: Ashfield, W. H. (AUTHOR), Longcope, D. W. (AUTHOR)

المصدر: Astrophysical Journal. 5/1/2021, Vol. 912 Issue 1, p1-12. 12p.

مصطلحات موضوعية: *SOLAR chromosphere, *CONDENSATION, *SOLAR flares, *FLUX (Energy), *SOLAR energy, *INVESTIGATION reports

مستخلص: Chromospheric condensation is a brief episode of downflow often accompanying energy release and evaporation in a solar flare. While this component of a flare reflects the energy release process only indirectly, it can be observed at high spatial and temporal resolution, even from the ground. It appears in spectroscopic observations of cooler lines, formed below ∼105 K, as a redshift that peaks and decays after less than 1 minute. In order to use this signature to infer characteristics of solar flare energy release, it is important to establish quantitative relationships with properties of the condensation. The initial investigation reported here does so after restricting consideration to energy transport via thermal conduction into a simplified, stratified chromosphere. We develop an analytical expression for the decay of a condensation propagating into a stratified atmosphere. This model provides a relationship between shock velocity and preshock density structure. We also use one-dimensional gasdynamic simulations to explore the dynamics of these shocks as they penetrate into the stratified chromosphere. We find that the peak downflow speed primarily reflects the energy flux into the chromosphere, while the product of this velocity and the redshift duration is proportional to the preshock density scale height as H ≃ 0.6u0τ. [ABSTRACT FROM AUTHOR]